Vehicle, antenna device for vehicle, and method thereof

Abstract

This disclosure relates to vehicles, antenna devices for vehicles, and methods thereof. In one embodiment, the vehicle includes: an integrated module disposed at any location within the vehicle, the integrated module including a low-noise amplifier and an antenna module; a metal frame arranged along a portion of the edge of the vehicle's rear windshield; a plurality of transparent antennas arranged within the rear windshield of the vehicle; a circuit board connected from the integrated module to a feed portion of each of the plurality of antennas; and cables configured to connect the feed portion of the integrated module to the circuit board.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of Korean Patent Application No. 10-2024-0190027, filed on December 18, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a transparent antenna device for vehicles. Background Technology

[0004] The following description provides background information on this disclosure only and does not constitute prior art.

[0005] As the services provided by vehicles diversify, various types of antennas are installed in vehicles. Roof antennas exist, which are typically mounted on the roof of the vehicle. Roof antennas are often made in a shape resembling a shark fin, so they are also known as shark fin antennas.

[0006] Figure 1 This is a diagram showing a conventional antenna installed on a vehicle.

[0007] refer to Figure 1 In a conventional scenario, a vehicle may include a roof-mounted antenna 100.

[0008] The vehicle may also include a glass antenna 130 integrated with a heating element. The glass antenna 130 may be located in an area other than the empty space 120 on top of the glass 110 to operate the high-mounted brake light (HMSL) and the built-in camera.

[0009] The glass antenna 130 is integrated with the heating element of the vehicle's glass 110 and is not easily identified as an antenna. Therefore, the glass antenna 130 does not affect the appearance, thereby improving the overall design integrity of the vehicle.

[0010] On the other hand, the roof antenna 100 is a component protruding from the exterior of the vehicle, which disrupts the overall aesthetic design and is often requested to be removed by users for aesthetic reasons. Furthermore, the problem with external antennas is that they increase air resistance when the vehicle is in motion, thus reducing fuel efficiency and degrading driving performance.

[0011] Recently, there has been a trend towards reducing the size of the roof antenna 100 or removing it altogether. This is because reducing the size of the roof antenna 100, which protrudes from the exterior of the vehicle, or removing it, can improve the vehicle's exterior design and reduce air resistance. However, if the size of the roof antenna 100 is reduced or it is removed, there are concerns that the frequency bands the vehicle can receive may be reduced or communication functionality may be degraded. For example, if the roof antenna 100 is removed, another antenna will be needed to replace it. Furthermore, when the size of the roof antenna 100 is reduced, it becomes difficult to properly arrange multiple radiators within the reduced internal space, and interference between radiators can occur due to the narrow spacing between them, leading to antenna performance degradation.

[0012] In order to reduce the size of the roof antenna 100 or remove the roof antenna 100, an antenna capable of performing all or some of the functions of the roof antenna 100 is required. Summary of the Invention

[0013] In view of the above, this disclosure provides a plurality of transparent antennas arranged in the area of ​​the rear windshield of a vehicle.

[0014] This disclosure provides a transparent antenna that can perform all or part of the functions of a rooftop antenna or assist the functions of a rooftop antenna.

[0015] The purposes of this disclosure are not limited to those described above, and other purposes not mentioned will be clearly understood by those skilled in the art from the following description.

[0016] Beneficial effects

[0017] According to one embodiment, multiple transparent antennas can be provided in the area of ​​the rear windshield of a vehicle.

[0018] According to the implementation method, a transparent antenna can be provided that can perform all or part of the functions of a roof antenna or assist the functions of a roof antenna. Attached Figure Description

[0019] Figure 1 This is a schematic diagram showing a conventional antenna structure used in vehicles.

[0020] Figure 2 This is a diagram illustrating a transparent antenna device for a vehicle according to an embodiment of the present disclosure.

[0021] Figure 3 This is a rear view showing a transparent antenna device for a vehicle according to an embodiment of the present disclosure when viewed from below.

[0022] Figure 4This is a graph showing the frequency-based reflection coefficient according to an embodiment of the present disclosure.

[0023] Figure 5 This is a graph showing the frequency-based insertion loss according to an embodiment of the present disclosure.

[0024] Figure 6 This is a graph showing the L5 band of the antenna according to this disclosure.

[0025] Figure 7 This is a graph showing the L1 band of the antenna according to this disclosure.

[0026] Figure 8 This is a diagram illustrating the distribution and flow direction of the electric field based on the distance between the GNSS antenna and the vehicle body, according to this disclosure. Detailed Implementation

[0027] In the following description, some exemplary embodiments of this disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals preferably denote the same elements, even though the elements are shown in different drawings. Furthermore, in the following description of some embodiments, for the purpose of clarity and brevity, detailed descriptions of known functions and configurations incorporated herein will be omitted.

[0028] Furthermore, terms such as first, second, A, B, (a), (b), etc., are used only to distinguish one component from another and do not imply or suggest the substance, order, or sequence of the components. Throughout this specification, when a component "comprises" or "includes" a component, that component is intended to further include other components without excluding them, unless specifically indicated otherwise. Terms such as "unit," "module," etc., refer to one or more units for performing at least one function or operation, and the one or more units may be implemented by hardware, software, or a combination of hardware and software.

[0029] Figure 2 This is a diagram illustrating a transparent antenna for a vehicle according to an embodiment of the present disclosure.

[0030] Figure 3 This is a rear view showing a transparent antenna for a vehicle according to an embodiment of the present disclosure when viewed from below.

[0031] refer to Figure 2 and Figure 3 The transparent antenna device for a vehicle according to this disclosure includes some or all of the following: an integrated module 300, a flexible circuit board 310, multiple antennas (multiple transparent antennas) 202, and a cable 301.

[0032] The integrated module 300 according to this disclosure can be disposed at any location in the vehicle. Preferably, the integrated module 300 is disposed on the left C-pillar 303 or the right C-pillar 303 of the vehicle. Specifically, preferably, on the left C-pillar 303 or the right C-pillar 303, the integrated module 300 is disposed adjacent to a plurality of antennas 202, which will be described later. The C-pillar 303 of the vehicle refers to the third frame positioned from front to rear among frames placed along the side of the vehicle. The C-pillar 303 is a support structure between the front and rear windows, connecting the roof and body of the vehicle and increasing the rigidity of the vehicle.

[0033] Preferably, the plurality of antennas 202 according to the present disclosure are positioned in a location that does not contact the heating element 201 formed on the rear windshield 200 of the vehicle.

[0034] When the integrated module 300 according to this disclosure is disposed in the C-pillar 303, the physical distance between the multiple antennas 202 and the low-noise amplifier (LNA) can be minimized. This is an important factor in receiving high-frequency signals; the shorter the path between the multiple antennas 202 and the LNA, the less RF path loss and the better the reception performance. Specifically, since the high-frequency signals in the GHz band processed by the GNSS antenna 322 and the CCS antennas 320 and 321 according to this disclosure have large path losses, reducing signal attenuation can maintain the reception quality of the antennas.

[0035] Furthermore, the C-pillar 303 is easily electrically grounded to the vehicle body, allowing the LNA and metal frame 304 to form a common ground. This common ground is used to suppress electromagnetic interference (EMI) and improve the antenna's signal quality. For example, if the integrated module 300 were located elsewhere than the C-pillar 303, it would be difficult to achieve a stable ground with the vehicle body, increasing the likelihood of noise being introduced into the received signal and leading to antenna performance degradation.

[0036] Furthermore, because the upper part of the rear windshield 200 of the vehicle has limited free space, it is difficult to install the integrated module 300 therein. However, the C-pillar 303 has free space, thus allowing the integrated module 300 to be stably installed. Therefore, assembly of the integrated module 300 can be made easier by workers, and the efficiency of the manufacturing process can be improved.

[0037] According to another embodiment of the present disclosure, the transparent antenna device for vehicles presents a structure in which the placement of the integrated module 300 can be flexibly applied according to the vehicle type.

[0038] Vehicles according to embodiments that include an A-pillar or a C-pillar have an integrated module 300 disposed in the C-pillar 303; however, station wagons and minivans include an A-pillar or a C-pillar and also include a structure extending to a D-pillar formed at the rear of the C-pillar. Therefore, when the integrated module 300 is applied to a station wagon or minivan, preferably, the integrated module 300 is placed on the D-pillar adjacent to the rear windshield 200.

[0039] The integrated module 300 according to this disclosure can be an integrated module structure including a CCS antenna (cellular communication system antenna, not shown) and a GNSS antenna (global navigation satellite system antenna, not shown). Here, the horizontal and vertical lengths of the CCS antenna disposed inside the integrated module 300 can be configured to 2 cm and 2 cm, respectively. The CCS antenna and GNSS antenna disposed inside the integrated module 300 can perform the same functions as the first CCS antenna 320, the second CCS antenna 321, and the GNSS antenna 322 described in this disclosure.

[0040] GNSS antenna 322 receives satellite signals to provide accurate position information. For this purpose, the received signals need to be amplified. Therefore, GNSS antenna 322 is configured to amplify the received signals by including a low-noise amplifier (LNA). Here, the LNA improves the performance of the GNSS system by maintaining the purity and strength of the signal through low-noise amplification of the GNSS signal.

[0041] Furthermore, considering appearance quality, cost, and assembly capabilities, the integrated module 300 according to this disclosure manufactures the antennas as an integrated structure and connects them as a whole. This simplifies the module's appearance, improves the overall aesthetics in vehicle design, and avoids installation space issues that may arise when designing individual antennas. The integrated module 300 reduces the number of components, thereby reducing the manufacturing cost of transparent antenna devices for vehicles and improving the efficiency of the assembly process.

[0042] According to this disclosure, CCS antennas 320 and 321 refer to antennas for receiving and transmitting signals from mobile communication networks such as 4G LTE and 5G NR. CCS antennas 320 and 321 perform various communication functions within the vehicle and provide vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, and connectivity to cloud-based services. CCS antennas 320 and 321 can support simple voice calls and data transmission, as well as high-speed data communication required by vehicle telematics systems and autonomous driving.

[0043] The CCS antennas 320 and 321 according to this disclosure operate primarily over a wide frequency range, including the Sub-6 GHz band (3.3 GHz to 4.2 GHz) and the millimeter-wave band (24 GHz to 40 GHz). The Sub-6 GHz band provides wide coverage and stable connectivity, while the millimeter-wave band offers wide bandwidth and supports high-speed data transmission. For example, representative frequencies in the Sub-6 GHz band are 3.5 GHz and 4.2 GHz, and wavelengths within this band are calculated to be approximately 8.57 cm and 7.14 cm, respectively. On the other hand, in the millimeter-wave band, the wavelengths are much shorter, and are measured, for example, to be approximately 1.15 cm in the 26 GHz band.

[0044] CCS antennas 320 and 321 feature multi-band characteristics to support a variety of frequencies. Since antenna size can be reduced in the high-frequency band, it is desirable to design a small antenna that maintains high efficiency without protruding beyond the vehicle's exterior. Specifically, in the Sub-6GHz band, the gap between the antenna and the vehicle body is adjusted to half (ë / 2) or 1 / 4 (ë / 4) of the effective wavelength to minimize the influence of the vehicle's internal structure and metal frame 304.

[0045] The GNSS antenna 322 according to this disclosure is an antenna designed to receive signals from a global satellite navigation system. The GNSS antenna 322 receives position, velocity, and time information transmitted from satellites and calculates a precise position.

[0046] GNSS antenna 322 operates in the L-band. The L-band is the frequency band used to transmit GNSS satellite signals and is typically located between 1.1 GHz and 1.6 GHz. Representative bands within the L-band are L1 (approximately 1.57542 GHz) and L5 (approximately 1.17645 GHz). Furthermore, GLONASS transmits signals at 1.602 GHz, and Galileo transmits signals at 1.17645 GHz and 1.27845 GHz. In this band, GNSS antenna 322 is designed to receive signals from each satellite system and, due to the characteristics of the signals, uses circular polarization to stably receive satellite signals.

[0047] The effective wavelength of the GNSS antenna 322 is determined by the lowest frequency received by the GNSS antenna 322. For example, the effective wavelength in the GPS L5 band (1.17645 GHz) is calculated to be approximately 25.48 cm. The effective wavelength is related to the period of the wave. The lower the frequency, the longer the wavelength. Because this length affects the size and arrangement of the GNSS antenna 322, the horizontal length (L1) of the GNSS antenna 322 according to this disclosure is equal to the effective wavelength length (λ) corresponding to the lowest operating frequency of the GNSS antenna. eff1 / 4 of ).

[0048] The flexible circuit board 310 according to this disclosure has a predetermined size to accommodate all the feed portions of a plurality of antennas 202 spaced apart from each other in the corner region of the rear windshield 200.

[0049] The flexible circuit board 310 is shaped to not overlap with the protrusions of the metal frame 304. Here, the protrusions of the metal frame 304 protrude partially and are formed with holes for assembly with other units constituting the vehicle using screws or bolts. However, the protrusions of the metal frame 304 can also be shaped to mitigate vibration and shock, or to guide each component into precise positions during the assembly process.

[0050] According to this disclosure, the plurality of antennas 202 include a GNSS antenna 322 and at least two CCS antennas 320 and 321.

[0051] According to this disclosure, two or more CCS antennas 320 and 321 may include a first CCS antenna 320 and a second CCS antenna 321.

[0052] According to this disclosure, the first CCS antenna 320, the second CCS antenna 321, and the GNSS antenna 322 each include a feed section 312, a feed section 313, and a feed section 314 connected to the flexible circuit board 310.

[0053] The first CCS antenna 320 includes a first feed section 312. The second CCS antenna 321 includes a second feed section 313. The GNSS antenna 322 includes a third feed section 314.

[0054] Each of the first feed section 312, the second feed section 313, and the third feed section 314 receives an electrical signal or transmits a signal from an external source. Each of the first feed section 312, the second feed section 313, and the third feed section 314 is configured to control the electrical signal flow of the GNSS antenna 322 and at least two CCS antennas 320 and 321 to minimize signal loss and maintain impedance matching between each antenna and external circuitry. Here, impedance matching refers to matching the impedance of the flexible circuit board 310 connected to each antenna.

[0055] According to this disclosure, a plurality of antennas 202 can be attached to and disposed on the rear windshield 200. Preferably, the plurality of antennas 202 are disposed on the upper left or upper right corner region of the rear windshield 200.

[0056] The GNSS antenna 322 is positioned closest to the C-pillar 303, which serves as the grounding point. Furthermore, at least two CCS antennas 320 and 321 can be placed in a direction away from the C-pillar 303 relative to the GNSS antenna 322.

[0057] The GNSS antenna 322 can be configured such that the feed portion is located at a distance of half the effective wavelength from the region in the metal frame 304 adjacent to the C-pillar 303.

[0058] When the GNSS antenna 322 according to this disclosure is placed in the upper left or upper right corner region of the rear windshield 200, the GNSS antenna is placed close to the vehicle body grounding, thus improving the antenna's circular polarization characteristics. Furthermore, the GNSS antenna can be spaced apart from the HMSL region 203 to reduce RF noise inflow. Additionally, the GNSS antenna can be placed close to the LNA module for GNSS placed on the C-pillar 303, thereby minimizing RF loss. On the other hand, when the CCS antennas 320 and 321 are placed in the corner, performance degradation may occur due to the influence of vehicle body grounding. Therefore, among the plurality of antennas 202 according to this disclosure, preferably, the GNSS antenna 322 is placed closest to the grounding C-pillar 303, and at least two CCS antennas 320 and 321 are placed in a direction away from the C-pillar 303 relative to the GNSS antenna 322.

[0059] This disclosure uses a flexible circuit board 310 connected to the feed section of each of a plurality of antennas 202.

[0060] Considering the losses of the flexible circuit board 310, the cable 301 is connected between the flexible circuit board 310 and the integrated module 300.

[0061] According to this disclosure, the cable 301 can be partially fixed to a fixing part, which is formed by attaching to the inner surface of the rear windshield 200.

[0062] Cable 301 is connected to feed portion 311 formed on flexible circuit board 310. Cable 301 is configured to prevent line loss on flexible circuit board 310. In addition, cable 301 can connect the flexible circuit board 310 attached to the rear surface of rear windshield 200 and the integrated module 300 placed on C-pillar 303.

[0063] Figure 4 This is a graph showing the frequency-based reflection coefficient according to an embodiment of the present disclosure.

[0064] Figure 5 This is a graph showing the frequency-based insertion loss according to an embodiment of the present disclosure.

[0065] refer to Figure 4 and Figure 5 According to this disclosure, multiple antennas 202 are attached to the rear windshield 200.

[0066] In this disclosure, a rear windshield 200 having a thickness of, for example, 3.5 mm can be used to perform simulations of reflection coefficient and insertion loss. Within the structure of the rear windshield 200, two channels with a spacing of 11 mm are provided, the spacing between the channels is set to 3 mm, and the length of the transmission line is designed to be 100 mm.

[0067] As a result of simulation analysis of the transmission characteristics of this disclosure using reflection coefficient and insertion loss, it can be seen that a loss of approximately 0.7 dB per 100 mm occurs in the transmission line. Furthermore, the insertion loss graph shows an insertion loss of approximately -0.67 dB in the 2.7 GHz band. This means that the plurality of antennas 202 according to this disclosure are configured to enable stable signal transmission in the corresponding frequency bands.

[0068] The reflection coefficient curve remains below -30 dB in the 0 GHz to 6 GHz frequency band, indicating that the reflection of the multiple antennas 202 applied to the rear windshield 200 is minimized, thereby achieving effective signal transmission.

[0069] The specific insertion loss and reflection coefficient plots will be described later.

[0070] The insertion loss graph according to this disclosure illustrates the characteristics of signal insertion loss with respect to frequency. Insertion loss is expressed as S-parameter values ​​S12 and S34. This represents the degree of loss of the input signal as it passes through the internal channel of the glass.

[0071] The insertion loss curve shown in the graph indicates a loss of -0.67 dB in the 2.7 GHz band. This means that the loss during signal transmission is very low, less than 1 dB, enabling efficient signal transmission. Furthermore, the insertion loss curve confirms a line loss of 0.7 dB per 100 mm, indicating that low loss is maintained even over a length of 100 mm.

[0072] Although the insertion loss curve shows a trend of gradual increase in loss with increasing frequency, the structure of the transparent antenna device for vehicles according to this disclosure maintains low loss even at high frequencies, thereby enabling stable communication performance in various frequency bands.

[0073] The reflection coefficient graphs according to this disclosure illustrate the characteristics of reflection loss according to frequency. The reflection coefficients are represented as S-parameter values ​​S11, S22, S33, and S44, and each S-parameter signifies the reflection characteristics at the corresponding port.

[0074] The reflection coefficient curves shown in the graphs all maintain values ​​below -20 dB for dB(S1,1), dB(S2,2), dB(S3,3), and dB(S4,4). A reflection loss below -20 dB means that very little signal is reflected within the frequency band, meaning that most of the input signal passes through to the next stage without reflection.

[0075] The peaks at different frequencies in the reflection coefficient curve indicate that reflection may occur at specific frequencies. However, since the peaks also remain below 20 dB, stable communication performance can be achieved across various frequency bands.

[0076] Figure 6 This is a graph showing the L5 band of the antenna according to this disclosure.

[0077] Figure 7 This is a graph showing the L1 band of the antenna according to this disclosure.

[0078] refer to Figure 6 and Figure 7 The L5 and L1 band curves of the antenna disclosed herein illustrate the degree to which the gain (achieved gain) in each band changes with the incident angle (Theta). The L5 and L1 bands are among the frequency bands of the GNSS antenna 322 and are important factors in evaluating the performance of vehicle antennas.

[0079] The L5 and L1 band curves of this disclosure represent information obtained through simulation to confirm the influence between the GNSS antenna 322 and the vehicle body.

[0080] Specifically, the RHCP circular polarization gain was calculated and compared while the distance between the third feed section 314, which serves as the center of the GNSS antenna 322, and the vehicle side of the C-pillar 303 was reduced from 200 mm to 60 mm. Simulations confirmed that the circular polarization gain increased as the distance between the GNSS antenna 322 and the vehicle side decreased.

[0081] The L5 band curve shows high gain over a small incident angle range, and the gain tends to gradually decrease as the angle increases. This means that when receiving signals in the L5 band at various angles, there may be signal loss at some angles, but GNSS antennas are designed to maintain stable signal performance at most angles.

[0082] The L1 band curves show a gradual change in gain relative to the angle of incidence, maintaining a stable gain without significant fluctuations depending on the angle. These characteristics indicate that the L1 band is designed to provide consistent performance across a variety of angles of incidence, thus enabling stable GNSS signal reception even when vehicles are in motion.

[0083] Furthermore, the table showing distance d and gain dBic discloses the gain based on distance d in the L5 and L1 bands. For example, when the distance is 60 mm, the gain is 0.4 dBic in the L5 band and 1.5 dBic in the L1 band. This means that within each band, the GNSS antenna can provide stable signal performance at a distance of 60 mm.

[0084] The GNSS antenna 322 according to this disclosure is designed to maintain a stable signal gain based on incident angle and distance conditions, and is optimized to exhibit high efficiency, particularly in the L5 and L1 bands of the GNSS antenna 322.

[0085] Figure 8 This is a diagram showing the distribution and flow direction of the electric field based on the distance between the GNSS antenna 322 and the vehicle body according to this disclosure.

[0086] refer to Figure 8 The distribution and flow direction of the electric field based on the distance between the GNSS antenna 322 and the vehicle side of the C-pillar 303 are shown.

[0087] Polarization refers to the phenomenon where the electric field (E-field) of an electromagnetic wave aligns along a specific direction. When the GNSS antenna 322 receives a signal, the closer the polarization of the received signal matches the polarization of the antenna, the higher the signal reception efficiency. Since GNSS signals are typically circularly polarized, the GNSS antenna 322 according to this disclosure is also designed for circular polarization.

[0088] Specifically, if the E-field strength increases, a stronger electric field will form around the GNSS antenna 322. This formed electric field can be stably aligned with the direction of the electric field around the GNSS antenna 322. In other words, as the E-field strength increases, the electric field forms more clearly in a specific direction, making it easier for the GNSS antenna 322 to form polarization in that direction. Specifically, when the GNSS antenna 322 is close to the vehicle side of the C-pillar 303, the vehicle side of the C-pillar 303 reflects and disperses the electric field, causing the E-field to flow in a specific direction. This makes the electric field flow required to maintain circular polarization more pronounced, which facilitates the reception of circularly polarized signals, such as GNSS signals. Therefore, as the distance between the GNSS antenna 322 and the vehicle side of the C-pillar 303 decreases and the E-field strength increases, a stable and strong flow of the electric field is formed. This allows the electric field to be more aligned and concentrated around the GNSS antenna 322, which is advantageous for the effective polarization formation required to receive GNSS signals.

[0089] Although exemplary embodiments of this disclosure have been described for illustrative purposes, those skilled in the art will recognize that various modifications, additions, and substitutions are possible without departing from the concept and scope of the claimed invention. Therefore, exemplary embodiments of this disclosure have been described for the sake of brevity and clarity. The scope of the technical concept of the embodiments is not limited by the illustrations. Therefore, those skilled in the art will understand that the scope of the claimed invention is not limited to the embodiments explicitly described above, but rather to the claims and their equivalents.

Claims

1. A vehicle comprising: An integrated module, located at any position in the vehicle, includes a low-noise amplifier module and an antenna module. A metal frame is arranged along a portion of the edge of the rear windshield of the vehicle; Multiple transparent antennas are arranged in the rear windshield of the vehicle; A circuit board, connected from the integrated module to the feed portion of each of the plurality of transparent antennas; as well as Cables are configured to connect the feed portion of the circuit board to the integrated module.

2. The vehicle according to claim 1, wherein, The integrated module is attached to the C-pillar or D-pillar of the vehicle, and the integrated module is configured to be adjacent to the plurality of transparent antennas.

3. The vehicle according to claim 1, wherein, The cable is secured to the inner surface of the rear windshield.

4. The vehicle according to claim 1, wherein, The plurality of transparent antennas include a global navigation satellite system antenna and at least two cellular communication system antennas.

5. The vehicle according to claim 4, wherein, The global navigation satellite system antenna is positioned closer to the grounding C-post or D-post than the at least two cellular communication system antennas.

6. The vehicle according to claim 4, wherein, The feed portion of the global navigation satellite system antenna is located at a distance of half the effective wavelength from the metal frame, and wherein the metal frame is positioned adjacent to either the C-pillar or the D-pillar.

7. The vehicle according to claim 1, wherein, The circuit board accommodates all the feed portions of the plurality of transparent antennas spaced apart from each other in the corner region of the rear windshield, and wherein the circuit board does not overlap with the protrusions of the metal frame.

8. The vehicle according to claim 4, wherein, The length of the global navigation satellite system antenna is equal to 1 / 4 of the effective wavelength length corresponding to the lowest frequency at which the global navigation satellite system antenna operates.

9. The vehicle according to claim 1, wherein, The circuit board and the plurality of transparent antennas are attached to or inserted into the inner surface of the rear windshield.

10. The vehicle according to claim 1, wherein, The plurality of transparent antennas do not come into contact with the heating element arranged in the rear windshield of the vehicle.

11. The vehicle according to claim 1, wherein, At least one antenna of the integrated module is configured to perform the same function as the plurality of transparent antennas arranged at the rear windshield.

12. The vehicle according to claim 1, wherein, The circuit board is a flexible circuit board.

13. An antenna device, comprising: Integrated modules, including low-noise amplifiers; Multiple transparent antennas are arranged in glass, including a global navigation satellite system antenna and at least two cellular communication system antennas; A circuit board connected to the feed section of each of the plurality of transparent antennas; and A cable connects the feed section of the circuit board to the integrated module.

14. The antenna device of claim 13, further comprising a metal frame disposed at the glass, wherein, The metal frame and the post form a common ground, wherein the metal frame is connected to the low-noise amplifier, and wherein the global navigation satellite system antenna is configured such that the feed portion of the global navigation satellite system antenna is located at a distance of half the effective wavelength from the region of the metal frame adjacent to the post.

15. The antenna device according to claim 13, wherein, The circuit board does not overlap with the protrusions of the metal frame.

16. The antenna device according to claim 13, wherein, The integrated module also includes at least one antenna.

17. The antenna device according to claim 13, wherein, The cable is fixed to the inner surface of the glass by a fixing part.

18. The antenna device according to claim 13, wherein, The circuit board is a flexible circuit board.

19. The antenna device according to claim 13, wherein, The integrated module and the plurality of transparent antennas are configured to operate in a complementary manner, such that at least one antenna in the integrated module provides signal redundancy for reception reliability.

20. A method for an antenna device, comprising: Determine the optimal distance between the global navigation satellite system antenna and the C-pillar or D-pillar of the vehicle body, wherein the optimal distance is determined based on the circular polarization gain; The global navigation satellite system antenna is positioned on the rear windshield of the vehicle at a determined optimal distance from the C-pillar or D-pillar on the side of the vehicle body, wherein the circular polarization gain increases as the distance between the global navigation satellite system antenna and the side of the vehicle body decreases; and By using the vehicle body as a reflective surface to align the direction of electric field flow around the global navigation satellite system antenna, the circular polarization characteristics of the global navigation satellite system antenna are enhanced.

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